The present invention relates to a mooring system for mooring a marine device at a preselected depth, and more particularly to a mooring system for mines.
Marine mines and other marine devices are launched from airborne platforms, submarines or surface ships. The physical limitation of each type of launch facility limits the overall weight and size of a combined anchor, mine and mooring mechanism. It is thus evident that a reliable, compact and lightweight mooring mechanism will permit either a greater amount of ordnance to be carried on each individual mine, thus increasing the effectiveness of the mine, or a greater number of mines or other marine devices to be carried and launched from the launching facility, thus increasing the effectiveness of the launching facility.
Prior art mooring systems include devices wherein a plummet line is connected to a mine which serves as a guide for the anchor to ride down to the ocean floor. The anchor is equipped with a hydrostatic gripper which is set to actuate at a selected depth thereby gripping the plummet line and pulling the mine down to a predetermined depth.
Devices have also been proposed in which a hydrostat is attached to the mooring line near the buoyant case so as to form a bight in the line which is not subject to the tension created by the anchor. As the anchor descends and reaches a set depth the hydrostat is actuated by the increased water pressure which causes the bight in the mooring line to be released. The momentary release of tension on the mooring line acts as a signal to a drum to cease payout of the mooring line.
Other devices have been proposed whereby the entire buoyant case and anchor sink to the ocean floor and the case is then released to ascend to the selected depth. A hydrostat attached to the case senses the selected depth and signals a mooring line drum on the anchor to cease payout of the mooring line.
The major disadvantage of the prior art devices is that they employ rotating mooring line drums with braking components so as to permit paying out of the mooring line. Because the rotating drums and brakes have been located on the anchors, which descend to the ocean floor, the drum and brake components have required structural strengthening to withstand the greater pressures found at the anchor depth, as opposed to tht lesser pressure found at the mooring depth. This results in a massive drum and brake structure which requires either a more massive device overall or, where the device is a mine, less ordnance carried by an individual mine.
Another disadvantage of the prior art devices is that the rotating drums and braking components of the mooring systems are mechanically complex in nature and are therefore subject to mechanical failures.